"I have been surprised by the proliferation of rallies worldwide," says Dr. McCarthy. "But I’m not sure what it means. I don’t know if this is just an outlet for people who share frustrations to come together for some cathartic exercise of political relief. But one of the things I think is interesting is there is a lot of anger and disaffection across the political spectrum."

Both American expatriates and foreign fans of "The Daily Show" and its host, Mr. Stewart, are organizing meet-ups Saturday – everywhere from London to Tel Aviv to Seoul – to concur with the rally on the Washington Mall.

While many criticize Stewart's gathering as lacking a clear focus, some Americans living abroad say it has inspired them to take part in next week's election. Mr. Stewart organized his rally in reaction to Glenn Beck's Aug. 28 gathering at the Lincoln Memorial.

"I feel like this year, more than previous years, people here are talking about how can you download a ballot, how can you vote early," says Kathryn Brown, a registered voter in Colorado who lives with her family in Paris. "There is much more of a grassroots effort to disseminate info on how to vote."

Ms. Brown is organizing a mini-rally at The Thistle Pub in Paris. At least 80 American expatriates and French nationals are expected to participate. "The French are addicted to politics. So anything that smells of political intrigue – they just love that stuff," she says.

Brown says the popularity of Stewart, coupled with the vocal protests of the tea party movement, may well have inspired expatriates to cast ballots in this election cycle. She spent $97 on postage fees to mail her absentee ballot from Paris earlier this week.

Meanwhile, in the northeastern Mexican city of Monterrey, Guillermo Zenizo Lindsey signed an Internet petition supporting Stewart's rally, although he's not a regular watcher of "The Daily Show."

"We need a rational discussion" about things such as health care and immigration reform, he says.

In Montreal, Marc Seltzer says he expects "50 or more supporters, curious, comedy-loving rally watchers and participants" at a mini-rally he's organizing Saturday. Mr. Seltzer, the local chair of Democrats Abroad, says he was interviewed on CBC radio today about the event, which he thinks will mostly draw expatriates like himself.

"The confluence of excitement about it may very well get people to vote," he says in a telephone interview.

Stewart is appealing for a "sane" conversation about the state of US politics and policy. But the idea of an entertaining afternoon is also expected to draw people to attend the Washington rally or watch it live on Comedy Central and CNN. It will include musicians The Roots, Jeff Tweedy, and Cheryl Crow and celebrities Don Novello and Sam Waterston.

If Stewart's rally is just "another political performance catalyzed by celebrity icons," however, it is unlikely it can change the super-charged nature of American political debate, says Harvard's McCarthy.

"Perhaps it will have an energizing affect," he says. "A spike in international or expatriate participation, I think, is a great thing. But I’m not super optimistic that will happen."

(Editor's note: Jon Stewart is not the creator of "The Daily Show," as this article originally stated. He became host in 1999, three years after it launched.)